Washington: A protein, which increases during an endurance exercise, may promote brain health, US researchers say. Researchers from the Dana-Farber Cancer Institute and Harvard Medical School found that the FNDC5 protein, when given to non-exercising mice, turned on genes that promote brain health and encourage growth of new nerves involved in learning and memory.

The findings, reported in the Cell Metabolism journal, explain the capacity of endurance exercise to improve cognitive function, particularly in older people. If this protein can be developed into a drug, it might lead to improved therapies for cognitive decline in older people. It can slow the toll of neuro-degenerative diseases such as Alzheimer and Parkinson, according to the researchers.

Earlier, the researchers reported that the protein is produced by muscular exertion and is released into the bloodstream as a variant called irisin. In the new study, they found that mice voluntarily running on a wheel for 30 days will have increased metabolic activity, which spurred a rise in FNDC5 protein. The increase of FNDC5 in turn boosted the BDNF brain-health protein in the hippocampus, the researchers said. Hippocampus is the part of the brain involved in learning and memory.

Having shown that FNDC5 is a molecular link between exercise and increased BDNF in the brain, the scientists looked into whether artificially increasing FNDC5 in the absence of exercise would have the same effect. So, they used a harmless virus to deliver the protein to mice, hoping the FNDC5 could reach the brain and raise BDNF activity. Seven days later, they examined the mice brains and observed a significant increase in BDNF in the hippocampus.

However, the researchers said they are not sure whether the protein that got into the brain is FNDC5 itself or irisin or perhaps another variant of the protein. Spiegelman added that further research is needed to determine whether giving FNDC5 actually improves cognitive function in other animals.